Gun barrell bushing structures



Nov. 19, 1968 F. A. PACHMAYR ETAL 3,411,405

GUN BARREL BUSHING STRUCTURES 2 Sheets-Sheet l Filed DSC. 29, 1966INVENTORS Fem/g A. Paauw/2 Y@ EDM/A20 ,8. MILLE@ T.Wo-AIN- Nov. 19, 1968F. A. PACHMAYR ETAL GUN BARREL BUSHING STRUCTURES Filed Dec. 29, 1966 2Sheets-Sheet 2 INVENTORS FQoA//c A. PACHA/w y( Fok/.42D B4 M n.45@ 1%@CZE r roem/5 Y United States ABSTRACT F THE DISCLOSURE A gun having aslide mounted for recoiling movement relative to the receiver of thegun, and relative to a barrel whose breech end s-wings slightlydownwardly upon recoil, and including a bushing disposed about andlocating the barrel and slidable axially therealong lupon recoil, and abushing retaining structure detachably carried by the slide, with thebushing having a radially outer preferably spherical surface movablycontacting and located by a mating essentially internal preferablyspherical bearing surface formed in the bushing retaining structure, ina relation `guiding the bushing for slight pivotal movement as thebreech end of the barrel swings downwardly.

This invention relates to improvements in guns, and particularly tomeans for accurately locating a gun barrel in a reciprocatin-g slide.

The guns of the present invention are of a `general type having a slidewhich recoils rearwardly relative to the barrel of the :gun and againstthe iniluence of a recoil spring upon eaoh ltiring operation, and inwhich the barrel of the gun has its forward end positioned by the slide,with the breech end of the barrel being mounted for limited rearward anddownward swinging movement as the slide recoils. A major object of theinvention is to provide improvements in the bus-hing structure which isprovided at the forward end of the gun and barrel for centering thebarrel in the slide, while still permitting the desired reciprocalmotion of the slide, and also permitting the slight downward swingingmovement of the breech end of the barrel. In conventional guns of thistype, the bushing locates the barrel only very inaccurately by reason ofthe necessity for this slight swinging movement of the barrel, so thatthe barrel is never held tightly and firmly in accurately xed positionby the slide, with resultant inherent inaccuracies and unreliability inthe firing characteristics of the gun.

Another object of the invention is to provide a bushing structure whichis more positively and rigidly secured to the slide than has beenpossible with most prior arrangements.

An assembly embodying the invention desirably includes a bushing elementproper which is disposed about the barrel and is slidable along thebarrel during recoiling movement of the slide, and which is locatedrelative to the slide by a coacting retaining structure. The bushing hasa radially outer surface which movably contacts a surface formed in theretaining structure in a relation guiding the bushing for limitedpivotal movement with the contained barrel as the breech end of thebarrel swings downwardly upon recoil. These two contacting surfaces arethemselves bearing surfaces which accurately locate the bushing and thebarrel during the limited pivotal movement, and are preferably sphericalsurfaces contacting over an extended area.

A unique manner of attachment of the bushing assembly or structure tothe slide is attained by employing as a connector element for thispurpose a plug which is carried by the slide and against which therecoil spring applies forward recoil resisting force to the slide. Thisplug may be connected to the slide in an appropriate atent ice manner,desirably by a threaded connection, and acts to prevent forwardseparation of the bushing assembly from the slide. More particularly,the plug may extend through a passage in a lower portion of a retainingpart by which the bushing proper is carried, and may have an enlargedhead for blocking forward motion of the retaining part. For ease inhandling, the plug and bushing structure may be interconnected as a unitprior to their application to the gun, and in a relation enablingrotation of the plug relative to the bushing assembly, but preventingrelative axial movement in either direction, to thereby maintain theintegrity of the two parts as a unit.

The above and other features and objects of the invention will be betterunderstood from the following detailed description of the typicalembodiments illustrated in the accompanying drawings, in which:

FIG. l is a side view, partially broken aJway, of a gun embodying theinvention;

FIG. la shows t-he bushing assembly of FIG. 1 removed forwardly from theslide;

FIG. 2 is a view taken on line 2 2 of FIG. l;

FIG. 3 is a vertical section taken on line 3 3 of FIG. l;

FIG. 4 is a view similar to a portion of FIG. l, but showing the partsin their recoiled positions;

FIG. 5 is a view similar to the forward portion of FIG. l, but showing aIvariational form of the invention;

FIG. 6 is a vertical section taken on line 6 6 of FIG. 5; and

FIG. 7 illustrates the manner of assembly of the FIG. 5 arrangement.

With reference first to FIG. l, there is shown at `10 an automaticpistol which is of a well known general type, and is completelyconventional in all respects except as to the parts shown at the leftend of FIG. l in the vicinity of the discharge end of gun barrel 11. Thegun includes a receiver 12 having a handle portion 13 within which thereis removably received a conventional magazine 14 containing a series ofcartridges 15 to be successively fired in the gun. The receiver ofcourse carries the usual trigger 16 by which hammer 17 is actuated to rea cartridge within the barrel 11.

To the upper side of receiver 12, there is movably mounted a slide 1Swhich is mounted by appropriate guideways extending along opposite sidesof the receiver and slide for horizontal reciprocal movement relative tothe receiver along the recoil axis 19, from the battery position of FIG.1 to the recoiled position of FIG. 4. The guideways may be ofconventional construction and are represented at 20 in the figures, andrestrain the slide against any motion other than the discussedhorizontal sliding movement relative to the receiver.

The forward portion of the slide, forwardly of a vertical forwardlyfacing shoulder 20 formed in the slide, is hollow, and contains thepreviously mentioned barrel 11. This barrel is tubular and disposedabout an axis 21, which in the battery position of FIG. l may beinclined very slightly with respect to recoil axis 19 of the slide. Thecartridge to be fired is contained within the breech end of the barrelat the location illustrated at 22 in FIG. 1, and is held in thatposition by engagement with vertical shoulder surface 20 of the slide.Externally, the barrel may have an outer straight cylindrical surface 23extending rearwardly from the muzzle end 24 of the barrel to thelocation of two upwardly projecting semi-circular lugs 25 which in thebattery position are received within mating semi-circular grooves 26formed in the undersurface of the top wall 27 of the slide.

At its underside, the breech end of the barrel has a downwardlyprojecting lug 27 which is pivotally connected by a pin 28 to a link 29,whose lower end is pivoted by a second link to the receiver, to enablethe breech end of the barrel to swing rearwardly and downwardly from theFIG. l position to the FIG. 4 position upon recoil.

The rearward recoiling motion of slide 18 is resisted by a coil spring31, which is disposed about a horizontal axis 32 located beneath andparallel to previously mentioned recoil axis i9. The rear end of spring31 exerts force in a rearward direction against the receiver through aspring guide 33, which may have a forward portion 34 projectingforwardly into the spring. The forward end of coil spring 31 exerts aforward force against slide 18 through a plug 3S, which also serves todetachably secure to the slide a bushing retaining or carrying element36, and a bushing proper 37 disposed about the barrel.

Plug is contained within a downwardly projecting enlargement 38 formedintegrally with and carried by slide 18. This enlargement 38 contains acylindrical passage 39 centered about axis 32 and extending in a frontto rear direction generally parallel to the gun barrel. The forward endof the slide, including its enlargement portion 38, may be cut off in avertical plane, to form a forward vertical surface 41 disposedperpendicular to axes 19 and 32, and extending about both the upperfront to rear passage or space 42 within which the barrel is received,and the lower passage 39 within which plug 35 is received.

The plug 35 has an outer cylindrical surface 43 of a diametercorresponding approximately to, and fitting closely within, the wall ofpassage 39 in the slide. At its rear end, the plug has external threads44, which are engageable with internal threads 45 formed in the wall ofpassage 39, to rigidly connect the plug to the slide. Extending into theplug from its rear end, there is formed a passage 46, which may becylindrical as shown, and which receives the forward end of coil spring31, with that spring bearing forwardly against a shoulder 47 in the plugto transmit forward force from the spring to the plug. The forward endof the plug may be slightly enlarged to form a circular head 48,typically having a screwdriver slot 49, and presenting a taperingfrusto-conical surface 50. Inwardly of head 51 of the plug, there may beprovided an annular groove 52 in the side of the plug, containing afriction element 53 typically taking the form of a neoprene O-ring,which projects radially outwardly beyond the cylindrical surface 43 ofthe plug to engage a mating surface and frictionally retain the plugagainst unscrewing rotation.

Bushing retaining element 36 extends vertically across the forward sideof the slide, and has the outline configuration illustrated in FIG. 2,to provide an enlarged upper portion 54 of a width corresponding to theupper portion of the slide, and a reduced width lower portion 55 of awidth corresponding to, and following the contour of, lower downwardlyprojecting portion 38 of the slide. At its rear side, element 36 has avertical planar surface S6, which abuts against forward planar surface41 of the slide. These surfaces 56 and 41 are retained in tight4engagement by plug 35, which extends through an opening 57 in the lowerportion 55 of element 35. This opening 57 has a cylindrical portion 58which is aligned with and of a diameter corresponding to, and forms ineffect a forward continuation of, passage 39 in the lower portion of theslide. At the forward end of surface 58, opening 57 has an enlargedportion forming a tapering frusto-conical annular surface 59 engaged bysurface 50 of the head of plug 35, to thereby transmit rearward forcefrom the plug to element 36. Thus, when the plug is screwed intoengagement with threads 45 of the slide, and is tightened, the plug actsto very securely and rigidly hold element 36 in the FIG. 1 position ofattachment to the slide.

At its upper side, bushing retaining element 36 has an upwardlyprojecting portion 60, which forms a forward sight for the gun, lying inthe vertical central plane 61 of the barrel, and coacting with the usualrearsight 62 to define the aiming axis of the gun.

Bushing element 37 takes the form of a ring disposed about thecylindrical surface 23 of the barrel, and having an internal cylindricalsurface 63 of a diameter corresponding substantially to, and slidablyengaging outer surface 23 of the barrel. The fit of these surfaces issufficiently close to maintain the bushing and barrel always coaxial,while still permitting the desired relative sliding movement of thebushing between the FIG. l and FIG. 4 positions. Externally, the bushinghas an annular partial spherical surface 64, which is centered about apoint 65 on the axis of the barrel, which center point is desirablylocated midway between the plane of the annular forward end surface 66of the bushing, and the plane of the annular rear end surface 67 of thebushing. Spherical surface 64 engages a correspondingly sphericallycurved annular internal surface 68 formed in the wall of a passage 69extending through the upper portion of element 36. Except at thelocation of bushing 37, the wall of passage 69 may be of straightcylindrical conguration, and centered about the recoil axis 19 of theslide, and be of a diameter slightly greater than the external diameterof the barrel to enable slight pivotal movement of the barrel relativeto element 36. To allow ample room for the reception of bushing 37,element 36 may have a tubular portion 70 projecting rearwardly therefromand beyond vertical planar surface 56 of element 36, and containing atleast a portion of the bushing.

To now describe a cycle of use of the gun, assume that the gun isinitially in the condition of FIG. 1, with a cartridge contained in thebreech end of barrel 11. In this condition, when trigger 16 is pulled,it actuates hammer 17 to lire the cartridge, and produce gases withinthe barrel acting to force the bullet forwardly therefrom. The reactionproduced by these gases exerts a rearward force through the cartridgecase against vertical shoulder surface 2t) of the slide, to causerearward recoiling motion of the slide from the FIG. l position to theFIG. 4 position, in which the spent cartridge case is ejectedautomatically, and a next successive cartridge is fed upwardly frommagazine 14 into the space in front of shoulder surface 20, to be forcedforwardly into the breech end of the barrel by the forward returningmovement of the slide under the influence of recoil spring 31.

As the slide 18 moves rearwardly during a recoiling motion, the breechend of the barrel 11 moves slightly rearwardly and downwardly aspermitted by swinging movement of link 29 between its FIG. 1 and FIG. 4positions, so that the connection provided between the barrel and slideby lugs 25 and notches 26 is temporarily broken. On the forwardreturning movement of the slide, shoulder surface 20 of the slideengages the breech end of the barrel to return it forwardly and upwardlyto the FIG. 1 battery position.

When the slide recoils, it carries with it bushing 37, `which slidesrearwardly along the outer surface of the barrel to the FIG. 4 position.As the breech end of the barrel swings downwardly, bushing 37 pivotsslightly within the bushing retaining element 36, as permitted by thebearing engagement of spherical surfaces 64 and 68, so that the barrelis free for the desired limited motion, and yet is very effectivelyguided and restrained and accurately positioned by bushing 37 andelement 36. Thus, in the battery position of FIG. 1, the forward end ofthe barrel is located very precisely relative to the slide and relativeto the forward sight 60 of the gun, to avoid the inaccuracies in aimingwhich occur in conventional guns as a result of the imprecision withwhich the forward end of the barrel is held and located.

When it is desired to disassemble the gun for cleaning or otherpurposes, plug 35 may be unscrewed by a screwdriver or other toolengaging groove 49, to break the threaded connection at 44-45, so thatthe plug may be pulled out of its passage 39 in the slide. This freeselement 36 for removal from the slide and barrel. The parts may bereassembled by merely positioning element 36 properly in the slide andabout the barrel, and then screwing plug 35 into its FIG. l position,with the friction element 53 engaging cylindrical surface 57 of element36, or cylindrical surface 39 of the slide, to retain the plug againstunscrewing rotation from its assembled position.

FIGS. 5 to 7 show a variational form of the invention in which plug 35ais connected to bushing or retaining element 36a by means of a pin 71received within a horizotal passage 72 in the lower portion of slide18a, at a location to be received within an annular groove 73 formed inthe outer surface of the plug. This pin retains the plug permanently inassembled relation with respect to element 36a, so that these two partsmay be handled as a unit when detached from the rest of the gun, and yetpin 71 enables rotary motion of plug 35a about its axis 32a for screwingthreads 44a of the plug into threads 45a of the slide. In FIGS. 5 and 6,these threads are illustrated as located near the forward end of theplug, rather than at its rear end as in the rst form of the invention.

Bushing 37a may be the same in FIGS. 5 and 6 as in the first form of theinvention, and has an outer spherical surface 64a engaging an internalspherical surface 68a in pivotal relation. Rearwardly of the transversevertical central plane 73 of the annular spherical groove defined bysurface 68a, the element 36a may have two diametrically oppositeinternal axially extending notches 74 of a size enabling initialinsertion of ring 37a into the groove in element 36a through thesenotches. This manner of insertion is illustrated in FIG. 7, in which thebushing 37a is shown in a horizontally extending position, to beinserted forwardly through notches 74 and then turned about its axis tothe FIG. 5 vertically extending position.

Instead of providing the installation grooves 74 of FIGS. 5 to 7, thebushing 37 of FIGS. 1 to 4 or the bushing 37a of FIGS. 5 to 7 may beinstalled by first forming the rear end of tubular portion 70 of element36a to a rearwardly aring condition, in which bushing 37 may be easilyinserted forwardly, and then spinning tubular portion 70 radiallyinwardly about the bushing and into conformity therewith. Conversely,instead of initially forming element 36 of a flaring condition, it maybe formed originally to its illustrated final condition, and bushing 37may be formed undersize and then expanded outwardly against the wall ofthe spherically shaped groove, and into conformity therewith. In eitherevent, the part which is either spun inwardly or expanded outwardlywould normally be of a softer material than the other part, and forexample might be formed of a brass or other non-ferrous bearingmaterial, while the other element 36 or 37 could be formed of hardenedsteel.

We claim:

1. A gun including a receiver, a slide mounted for recoiling movementrelative to said receiver, a barrel mounted for slight upward anddownward swinging movement of the breech end of the barrel relative tosaid receiver during said recoiling movement of the slide, a bushingdisposed about and locating said barrel and slidable therealong axiallyof the barrel upon said recoiling movement of the slide, and a bushingretaining structure detachably carried by the slide, said bushing havinga radially outer surface movably contacting and located by a matingessentially internal ybearing surface formed in said retaining structurein a relation guiding the bushing for slight pivotal movement relativeto said retaining structure and said slide abo-ut an axis disposedessentially transversely of the barrel upon said slight swingingmovement of the breech end of the barrel.

2. A gun as recited in claim 1, including a connection for detachablysecuring said retaining structure to the forward end of said slide.

3. A gun as recited in claim 1, including a recoil spring, a plug forretaining said spring, 'and means for detachably connecting said plug tothe slide, said plug being constructed to hold said retaining structureagainst detachment from the slide.

4. A gun including a receiver, a slide mounted for recoiling movementrelative to said receiver, a barrel mounted for slight upward anddownward swinging movement of the breech end of the barrel relative tosaid receiver during said recoiling movement of the slide, a bushingdisposed about and locating said barrel and slidable therealong axiallyof the -barrel upon said recoiling movement of the slide, a recoilspring, a plug against which said spring exerts force in a forwarddirection, means for detachably securing said plug to said slide, andmeans for transmitting force in a forward direction from said 'bushingto said plug so that the plug retains the bushing against forwardremoval from the slide.

5. A gun as recited in claim 4, in Vwhich said last mentioned meansinclude a structure for retaining said bushing and containing a passagethrough which said plug extends, said plug having a shoulder bearingrearwardly against said structure.

6. A gun including a receiver, a slide mounted for recoiling movementrelative to said receiver, a barrel mounted for slight upward anddownward swinging movement of the breech end of the barrel relative tosaid receiver during said recoiling movement of the slide, a bushingdisposed about and locating said barrel and slidable therealong axiallyof the barrel upon said recoiling movement of the slide, a recoil springfor resisting rearward movement of the slide, a plug against which saidspring exerts force forwardly, and interengaging threads on said plugand said slide for transmitting said forward force of the spring to saidslide.

7. An assembly to be applied to a gun having a barrel, a recoilingslide, and a recoil spring; said assembly including a structure to bereceived about said barrel and Ibe carried by the slide for recoilingmovement therewith, a plug to receive the forward force of said spring,and a connection between said plug and said structure connecting theplug to said structure prior to their attachment to the gun and mountingthe plug for rotation relative to said structure but retaining the plugagainst relative axial movement in a forward direction and also againstrelative axial movement in a rearward direction.

8. A gun including a receiver, a slide mounted for recoiling movementrelative to said receiver, a barrel mounted for slight upward anddownward swinging movement of the breech end of the barrel relative tosaid receiver during said recoiling movement of the slide, a bushingdisposed about and locating said barrel and slidable therealong `axiallyof the barrel upon said recoiling movement -of the slide, and a bushingretaining `structure detachably carried by the slide, said bushinghaving a radially outer surface movalbl-y contacting and located by amating i earing surface for-med in said retaining structure in arelation guiding the bushing for slight pivotal movement relative tosaid retaining structure and said slide about an axis disposedessentially transversely of the barrel upon said slight swingingmovement of the breech end of the barrel, said engaging surfaces of thebushing and retaining structure being curved substantially sphericallyabout a center located substantially on the axis of said barrel. 9. Agun as recited in claim 8, in which said bushing 1s a ring having acylindrical inner surface slidably contacting the barrel, said retainingstructure being disposed about said bushing, said spherical surface ofthe retaining structure being engageable in opposite axial directionsagainst the outer bushing surface in a relation positively locating thebushing axially.

10. A gun including a receiver, a slide mounted for recoiling movementrelative to said receiver, a barrel mounted for slight upward anddownward swinging movement of the `breech end of the 4b-arrel relativeto said recelver during said recoiling movement of the slide, a bushingdisposed about and locating said b-arrel and slidable therealong axiallyof the barrel upon said recoiling movement of the slide, a bushingretaining structure detachably carried by the slide, said bushing havinga radially outer surface movably contacting and located by a matingbearing surface formed in said retaining structure in a relation guidingthe bushing for slight pivotal movement relative to said retainingstructure and said slide about an axis disposed essentially transverselyof the barrel upon said slight swinging movement of the breech end ofthe barrel, a recoil spring, a plug for retaining said spring, andinterengaging threads on the plug and slide for detachably connectingsaid plug to the slide, -said plug being constructed to hold saidretaining structure against detachment from the slide.

11. A gun including a receiver, a slide mounted for recoiling movementrelative to said receiver, a barrel mounted for slight upward anddownward swinging movement of the breech end of the barrel relative tosaid receiver during said recoiling movement of the slide, a bushingdisposed about and locating said barrel and slidable therealong axiallyof the barrel upon said recoiling movement of the slide, a bushingretaining structure detachably carried by the slide, said bushing havinga radially outer surface movably contacting and located by a matingessentially internal rbearing surface formed in said retaining structurein a relation guiding the bushing for slight pivotal movement relativeto said retaining structure and said slide about an axis disposedessentially transversely of the barrel upon said slight swingingmovement of the breech end of the barrel, said retaining structurecontaining a Ifirst passage extending in a front to rear direction forreceiving said bushing and barrel, and containing a second front to rearpassage therebeneath, there being a recoil spring, and a plug forretaining said spring and extending through said second passage andacting rearwardly against the retaining structure in a relation holdingthe latter against removal from the slide.

12. A gun as recited in claim 11, including interengaging threads onsaid plug and slide for securing the plug to the slide.

13. A gun as recited in claim 11, including means forming a rotaryconnection between the plug and retaining structure before theirconnection to the slide and securing them against axial separation ineither direction but permitting rotation of the plug relative to theslide.

14. A gun as recited in claim 8, in which said bushing is a ring havinga cylindrical inner surface slida-bly contacting the barrel, saidretaining structure having a first portion located forwardly of saidslide and having an essentially tubular portion projecting rearwardlyinto the slide and disposed about said bushing, said mating sphericalsurface of the retaining structure being contained within and formed bysaid essentially tubular portion of the retaining structure and beingengageable in opposite axial directions against the outer bushingsurface in a relation positively locating the bushing axially, saidfirst portion of the retaining structure containing a passage extendingtherethrough generally parallel to said barrel at a location beneath thebarrel, a recoil spring for resisting recoiling movement of the sliderelative to the receiver, a plug against which said spring exerts forcein a forward direction and extending through said passage in theretaining structure, and threads on said plug and slide engageable toconnect the plug to the slide, said plug having a head for exertingrearward force against said retaining structure to retain the latteragainst separation from the Slide.

1S. An assembly to be applied to a gun having a barrel, a recoilingslide, and a recoil spring; said assembly including a structure to bereceived about said barrel and be carried by the slide for recoilingmovement therewith, Ia plug to receive the forward force of said spring,and a connection between said plug and said struct-ure connecting theplug to said structure prior to their attachment to the gun and mountingthe plug for rotation relative to said structure but retaining the plugagainst relative axial movement in either direction, said connectionincluding a pin carried Iby said structure and received Within a groovein said plug.

16. A gun including a receiver, a slide mounted for recoiling movementrelative to said receiver, a barrel mounted for slight upward anddownward swinging movement of the breech end of the barrel relative tosaid receiver yduring said recoiling movement of the slide, a bushingdisposed about and locating said barrel and slidable therealong axiallyof the barrel upon said recoiling movement of the slide, a bushingretaining structure detachably carried by the slide and relative towhich said bushing is free for slight pivotal movement with the barrel,and a forward sight for the gun carried by said retaining structure.

References Cited UNITED STATES PATENTS 984,519 2/1911 Browning 89-163X2,489,816 ll/l949 Reilly 89-163 3,158,064 11/1964 Charron 89-196BENJAMIN A. BORCHELT, Primary Examiner. S. C. BENTLEY, AssistantExaminer.

